The answer is your issue with blowing the breaker is not at all related to your converter (well technically the converter is also sucking some AC power, charging the batteries or running anything DC that may be turned on like lights or water pump), nor is it related to your inverter/charger thing.
It’s straight AC power from the shore plug to the microwave and AC. And it’s not unreasonable to think you can’t run both of them at the same time without exceeding the 30amps your breaker is kicking at.
Most likely you have no issues at all other than overloading the main AC breaker.
Of course you don’t say “which” breaker but I’m presuming the camper main, not the pedestal main (although it would be the same cause unless maybe a weak breaker, also a possibility with the camper main).
